                    :synsem {:agr {:number number-agreement}
                             :reflexive false
                             :cat :noun
-                            :mod '()
+                            :mod []
                             :propernoun propernoun
                             :sem {:number number-agreement}}
                    :head {:phrasal false

       :synsem {:cat cat
                :slash true
                :subcat {:1 second-arg
                         :2 '()}}
       :comp {:synsem first-arg}
       :head {:synsem {:cat cat
                       :subcat {:1 first-arg
                                :2 second-arg}}}})
    {:synsem {:aux false}
     :head {:synsem {:aux false}}
     :comp {:synsem {:subcat '()
                     :case :nom
                     :cat :noun}}}


    )])

(defn aux-is-head-feature [phrase]
  (cond (= :verb (get-in phrase [:synsem :cat]))
        (unify-check phrase
                (let [ref (atom :top)]
                  {:synsem {:aux ref}
